Chromosoma

, Volume 112, Issue 4, pp 190–200

Replication labeling patterns and chromosome territories typical of mammalian nuclei are conserved in the early metazoan Hydra

  • Olga Alexandrova
  • Irina Solovei
  • Thomas Cremer
  • Charles N. David
Research Article

DOI: 10.1007/s00412-003-0259-z

Cite this article as:
Alexandrova, O., Solovei, I., Cremer, T. et al. Chromosoma (2003) 112: 190. doi:10.1007/s00412-003-0259-z

Abstract

To investigate the evolutionary conservation of higher order nuclear architecture previously described for mammalian cells we have analyzed the nuclear architecture of the simple polyp Hydra. These diploblastic organisms have large nuclei (8–10 μm) containing about 3×109 bp of DNA organized in 15 chromosome pairs. They belong to the earliest metazoan phylum and are separated from mammals by at least 600 million years. Single and double pulse labeling with halogenated nucleotides (bromodeoxyuridine, iododeoxyuridine and chlorodeoxyuridine) revealed striking similarities to the known sequence of replication labeling patterns in mammalian nuclei. These patterns reflect a persistent nuclear arrangement of early, mid-, and late replicating chromatin foci that could be identified during all stages of interphase over at least 5–10 cell generations. Segregation of labeled chromatids led after several cell divisions to nuclei with single or a few labeled chromosome territories. In such nuclei distinct clusters of labeled chromatin foci were separated by extended nuclear areas with non-labeled chromatin, which is typical of a territorial arrangement of interphase chromosomes. Our results indicate the conservation of fundamental features of higher order chromatin arrangements throughout the evolution of metazoan animals and suggest the existence of conserved mechanism(s) controlling this architecture.

Abbreviations

CT

Chromosome territory

BrdU

Bromodeoxyuridine

IdU

Iododeoxyuridine

CldU

Chlorodeoxyuridine

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Olga Alexandrova
    • 1
  • Irina Solovei
    • 2
  • Thomas Cremer
    • 2
  • Charles N. David
    • 1
  1. 1.Department of Biology II, Cell and Developmental BiologyLudwig Maximilians UniversityMunichGermany
  2. 2.Department of Biology II, Anthropology and Human GeneticsMunichGermany